Portable post driver



March 8, 1955 J. B. RICHARDSON 2,703,479

PORTABLE POST DRIVER Filed Dec. 17, 1951 50 M92 44 IO I4 60 H 42 I2 I6*6 j 0 [k -26 30 E -za James 5. Richardson 2H INVENTOR.

9 BY M L/W United States Patent PORTABLE POST DRIVER James B.Richardson, Honolulu, Territory of Hawaii Application December 17, 1951,Serial No. 262,097

4 Claims. (Cl. 61-76) This invention relates to new and usefulimprovements and structural refinements in mechanical devices fordriving posts into the ground, particularly fence posts, or the like,and the principal object of the invention is to provide a portabledevice of the character herein described, which may be quickly andeasily applied to a post, which may be conveniently controlled so as toeffect the post driving operation in a series of successive impacts, andwhich includes means for accommodating posts of different diameters.

Some of the advantages of the invention reside in its simplicity ofconstruction, in its convenient and expeditious operation and in itsadaptability to economical manufacture.

With the above more important objects and features in view, and suchother objects and features as may become apparent as this specificationproceeds, the invention consists essentially of the arrangement andconstruction ofi1 parts as illustrated in the accompanying drawings, inw 1c Figure 1 is a perspective view of the invention per se;

Figure 2 is a vertical sectional view, taken substantially in the planeof line 2-2 of Figure 1 and illustrating the invention applied to apost, and

Figure 3 is a horizontal sectional view, taken substantially in theplane of the line 33 in Figure 2.

Like characters of reference are employed to designate like parts in thespecification and throughout the several views.

Referring now to the accompanying drawings in detail, the inventionconsists of a portable post driver which is designated generally by thereference character and embodies in its construction a substantiallyhorizontal platform 12 which is provided at opposite longitudinal edgesthereof with pairs of ears 14 carrying parallel handles 16, whereby theentire device may be manually supported.

A flanged adapter 18 is secured to the underside of the platform 12 bysuitable screws 20 and has a screw threaded portion 22 in which issecured the upper end of a tubular post receiving socket 24.

The post to which the invention is applied is indicated at 26, and it isto be noted that a tubular insert '28 is slidably and removablypositioned in the socket 24 and is sustained therein by a set screw 30,so that by employing inserts 28 of different wall thicknesses, thesocket 24 may accommodate posts of different diameters. Needless to say,if the diameter of the post 26 is substantially equal to the insidediameter of the socket 24, the insert 28 is not employed.

The platform 12 is provided with a circular aperture or opening 32 whichis coaxial with the socket 24 and slidably accommodates a cylindricalanvil 34, having an enlarged head 36 provided at the lower end thereof.The upper end of the socket 24 affords an annular seat 38 which isspaced downwardly from the underside of the platform 12 and the head 36is reciprocable in the space between the seat 38 and the platform, aswill be hereinafter more fully apparent.

The upward sliding movement of the anvil 34 is limited by adjustablestuds 40 which extend downwardly through the platform 12' and areprovided at their upper ends with suitable lock nuts 42, the lower endsof the studs 40 being engageable with the head 36 to provide adjustablestop means for the anvil at the upper end of its stroke. At the lowerend of its stroke, the head 36 of 2,703,479 Patented Mar. -8, 1955 theanvil 34 is engageable with the seat 38, as will be clearly apparent.

A suitable electric motor 44 is mounted on the upper surface of theplatform 12, the armature shaft 46 of the motor being journaled in anauxiliary bearing 48 and carrying a cam 50 which is disposed immediatelyabove the anvil 34. The cam 50 has a relatively low lobe 52 and arelatively high lobe 54 at the diametrically opposte sides thereof, andit is to be observed that when the head 36 of the anvil 34 is inabutment with the stop screws 40, the cam 50 is disengaged from theanvil, as shown in Figure 2.

When the invention is placed in use it is applied to the fence post 26so that the latter is slidably received in the socket 24, or the insert28, as the case may be, and with the head 36 abutting the screws 40 andthe cam 50 disengaged from the anvil 34, the motor 44 is energized so asto rapidly rotate the cam. When the cam is in motion, the relativelyhigh lobe 54 thereof will impact the upper end surface of the anvil 34and while the inherent inertia of the entire apparatus will tend tosustain the platform 12 stationary, so to speak, in the hands of theuser, the anvil 34 will be driven downwardly, thus driving the post 26into the ground until the head 36 abuts the shoulder 38. Thereupon,continued rotation of the cam 50 will result in its disengagement fromthe anvil 34 and, by virtue of its own weight, the entire apparatus willdescend, so to speak, relative to the post 26 and anvil 34 so that aposition is again reached where, as shown in Figure 2, the head 36 abutsthe stop screws 40. It will be apparent from the foregoing thatcontinued rapid rotation of the cam 50 will result in a series ofconsecutive impacts being delivered to the post, thereby driving thelatter in an inching manner into the ground. 3

Means are provided for conveniently controlling the operation of themotor 44, these means including a control yoke or lever 56 having ahandle portion 58 at one end disposed adjacent one of the aforementionedhand grips 16, while the other end of the yoke 56 is pivoted at 60 tosuitable brackets 62 on the platform 12. The yoke 56 straddles the cam50 and is operatively connected by means of a pivoted link 64 to arepeating type electric switch which is alternately closed and opened bysuccessive depressions of the yoke 56. This switch is mounted on theplatform 12 for controlling the motor 44. The yoke 56 is urged upwardlyby a pair of compression springs 68 which are interposed between theyoke and the platform 12, and when the yoke is in its upper position andthe switch 66 is open, the motor 44 is stationary. However, bydepressing the handle 58 in the direction of the adjacent hand grip 16and promptly releasing the handle, the switch 66 will be closed and themotor 44 energized. It is to be noted that in this manner the same handof the operator may be used for controlling the movement of the yoke 56as well as for grasping the adjacent of the hand grips 16, while theslecoid hand grip, of course, is grasped by the other It is also to benoted that the yoke 56 is engageable with the upper surface of the anvil34 at the opposite sides of the cam 50, so that when the device is atrest, downward movement of the yoke will first raise the platform 12relative to the anvil, so that the anvil is spaced from the cam inreadiness for the first impact as soon as the motor is energized by theswitch 66.

It is believed that the advantages and use of the invention will bereadily understood from the foregoing disclosure and accordingly,further description thereof at this point is deemed unnecessary.

While in the foregoing there has been shown and described the preferredembodiment of this invention, it is to be understood that minor changesin the details of construction and arrangement of parts may be resortedto without departing from the spirit and scope of the invention asclaimed.

Having described the invention, what is claimed as new is:

1. A portable post driver, comprising a manually supported platformhaving an opening therein, a substantially cylindrical post-receivingsocket provided at the underside of said platform coaxially with saidopening, said socket being larger in diameter than said opening andbeing provided with an annular shoulder spaced downwardly from andopposing the underside of the platform, an anvil reciprocable verticallyin said opening and provided at its lower end with a diametricallyenlarged post engaging head disposed in the space between the platformand said shoulder, said shoulder constituting an abutment for said headwhen the latter is at the lower end of its stroke, adjustable stop meansfor said head at the upper end of its stroke, a motor mounted on saidplatform, and an impact delivering member actuated by said motor andengageable with the upper end of said anvil thereby imparting a downwardimpact to said anvil.

2. The device as defined in claim 1 wherein said motor includes arotatable shaft, said impact delivering member comprising a cam securedto said shaft and including a ,low lobe and a high lobe, the low lobe ofsaid cam being spaced upwardly from said anvil when said head engagessaid adjustable stop means.

3. The device as defined in claim 1 together with a control for saidmotor provided on said platform.

4. The device as defined in claim 1 together with a control for saidmotor provided on said platform and including a yoke pivoted to theplatform and engageable with the upper end of said anvil.

References Cited in the file of this patent UNITED STATES PATENTS

